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"INDUSTRIAL" USB Propplug design UPDATED TO REV-D - Different USB Connector — Parallax Forums

"INDUSTRIAL" USB Propplug design UPDATED TO REV-D - Different USB Connector

DavidMDavidM Posts: 630
edited 2009-04-24 11:42 in Propeller 1
HI,

Further to my last post regarding the prop-plug resetting the prop device each time a usb cable is inserted,
I have made a complete design ( USING EAGLE CAD ) for a small PCB with the circuit mentioned from my last post.

I plan to use the ( MUSBD111-XX) AMPHENOL HARSH ENVIRONMENT USB TYPE B Connector and dust cover. ( images attached)

The idea of this design is to add to an existing prop powered device, a USB port via a IP67 panel connection.
The circuit will allow normal USB comms , but if the user needs to upload new firmware to a prop device then the RESET ENABLE Line needs to be pulled hi ( via your own spin function) and then firmware can be loaded via SPIN or other similar software. I am hoping this will work !

I have added a through-hole LED mounting option for the TX & RX LEDS to poke through the panel as well.


Any comments welcome.


regards

Dave M

Post Edited (DavidM) : 4/24/2009 9:09:13 AM GMT

Comments

  • SRLMSRLM Posts: 5,045
    edited 2009-04-20 07:40
    So it won't be compatible with the current Prop plug? I think that will limit it's use in existing designs, and probably in future ones as well. Is there some way that you could include a spot where users can solder a jumper to make it like a regular Prop plug?
  • DavidMDavidM Posts: 630
    edited 2009-04-20 07:53
    Hi SRLM,

    I am not sure what you mean by "COMPATIBLE" with the current prop-plug.

    This design is meant to be used in a FINISHED DESIGN where the user would need normal USB functionality ( but without all the unnecessary resetting).
    BUT on the RARE occasion the user/operator needs to update the prop firmware, then the user would initiate a "UPDATE FIRMWARE" routine from the existing PROP DEVICE.

    While you are developing on your prop device you would just need to use the parallax prop-plug.

    I guess i could add a small jumper to "DISABLE THE ENABLING??" if you wish to use the industrial prop-plug instead of the standard one. This could also be made into a switch as well.


    regards

    Dave M
  • heaterheater Posts: 3,370
    edited 2009-04-20 07:54
    "RESET ENABLE Line needs to be pulled hi ( via your own spin function)"

    So if one downloads a Spin prog. that never touches RESET ENABLE one can not download any more.

    Is that really so ?

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  • DavidMDavidM Posts: 630
    edited 2009-04-20 08:00
    Hi Heater!

    yes that's how its supposed to work.

    if you want to enable firmware updating , then you need in your application a routine to ENABLE the device. ( a few lines of code )

    Then you can update the firmware via normal means. ( But note I have not tested this circuit yet, i am posting it here to get feedback)

    regards

    Dave M
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2009-04-20 08:16
    Dave,

    You need to test your circuit first to make sure you can get a clean reset. I'm not sure if this is a problem, but there's a chance that as soon as /RST is pulled low, the Prop will tristate all its pins, which would disable the reset immediately, causing a runty pulse. This could result in an incomplete reset of the chip. The Propeller datasheet doesn't state how long the reset pulse has to be; so, unless someone in the know can chime in here, experimentation may be your only recourse.

    -Phil
  • SRLMSRLM Posts: 5,045
    edited 2009-04-20 08:26
    If you could fit a switch somewhere on there then it would allow you to update systems that may or may not have the required firmware on the Prop.
  • dMajodMajo Posts: 855
    edited 2009-04-20 08:46
    R1+L2||L4 and R2+L3||L3: in this way you must have both leds internal+external. If you want the choice to add or not the external one you need one resistor for each led.
  • DavidMDavidM Posts: 630
    edited 2009-04-20 09:15
    Hi dMajo,

    I have set up the LEDS in parallel , BUT ONLY ONE should be placed, either INTERNAL or the EXTERNAL led. ( or even none of them )

    thanks

    Dave M
  • DavidMDavidM Posts: 630
    edited 2009-04-20 09:16
    Hi SRLM

    I will add a 2 pin header for an optional switch, so that the enabling function can be controlled MANUALLY.

    thanks

    Dave M
  • DavidMDavidM Posts: 630
    edited 2009-04-20 09:19
    Hi Phil,

    You could be right!

    The other option is to use a ANALOG SWITCH maybe?


    I know I will need to test.

    regards

    Dave M
  • DavidMDavidM Posts: 630
    edited 2009-04-23 02:46
    OK,

    I will do this a different way. By default the device will behave like the standard propplug.

    I will use an ANALOG SWITCH instead of the mosfet.
    The analog switch I have chosen is the Texas-Instruments-SN74LVC1G66DBVR
    This will be powered by a 3.3 v supply from the header.

    The first 4 pins of the header J2 are arranged the same as the current propplug.

    By default the analog switch will be pulled hi ( via the 10K resistor R3) which will allow the USB DEVICE to behave just like the standard PROPPLUG.

    By pulling the Enable line Low, via SPIN code ( which can be part of your start up routine) , you can then disable the reset line so that plugging and unplugging the UDB connector will not reset the PROPELLER DEVICE.

    I have updated the Schematic and the PCB Layout.

    Any comments welcome.

    thanks

    Dave M
  • mctriviamctrivia Posts: 3,772
    edited 2009-04-23 03:14
    if you swap ren and 3.3V your plug would be compatible with my propmod secure which has a 5 pin programing header. Looks nice.

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    Need to make your prop design easier or secure? Get a PropMod has crystal, eeprom, and programing header in a 40 pin dip 0.7" pitch module with uSD reader, and RTC options.
  • DavidMDavidM Posts: 630
    edited 2009-04-23 03:31
    HI mctrivia

    I swapped pins 5 & 6.


    regards


    Dave M
  • mctriviamctrivia Posts: 3,772
    edited 2009-04-23 03:47
    are you planning to build these or looking for someone to build for you?

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Need to make your prop design easier or secure? Get a PropMod has crystal, eeprom, and programing header in a 40 pin dip 0.7" pitch module with uSD reader, and RTC options.
  • DavidMDavidM Posts: 630
    edited 2009-04-23 03:53
    Hi mctrivia,

    I am getting a local PCB manufacturer to make some of these, along with my IP-RS485 boards as well. They will be HAND SOLDERING some of each so I can test them as well as remake some more with any mods.

    I will be incorporating these circuits into a larger board/project I am working on as well.

    if this board works, do you think it possible to sell them?

    regards

    Dave M
  • mctriviamctrivia Posts: 3,772
    edited 2009-04-23 03:58
    definetly if you can price under the propplug price. above you will not sell as much but there is a market for it. It fixs the major issue with keeping the propplug attached. Depending on cost and shipping cost I would be willing to buy 2.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Need to make your prop design easier or secure? Get a PropMod has crystal, eeprom, and programing header in a 40 pin dip 0.7" pitch module with uSD reader, and RTC options.
  • DavidMDavidM Posts: 630
    edited 2009-04-23 05:11
    Hi mctrivia

    Yes i guess i could sell these, at least to cover costs for my development,
    I need to source other kinds of USB Connectors, My main aim is IP67/IP68 type for industrial /outdoor use. each different conector will require a different PCB Design. I am in the process of getting samples.

    regards

    Dave M
  • DavidMDavidM Posts: 630
    edited 2009-04-24 09:06
    Hi,

    I have chosen a different connector, the BULGIN PX0447 as it is smaller than the other one.

    Some Questions

    Q1) According to the FTDI spec sheet ( page 22) for this Chip, they suggest to use a small ferrite bead ( MI0805K400R-10) , is this necessary?

    Q2) are the resistors to the TX & RX pins of the IC required and/or are they the right value?


    Q3) Will the ANALOG Switch circuit work?


    regards

    Dave M
  • LeonLeon Posts: 7,620
    edited 2009-04-24 10:51
    The ferrite bead will probably be needed if CE or FCC approval is required.

    Leon

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  • Cluso99Cluso99 Posts: 18,069
    edited 2009-04-24 11:14
    You should checkout the Diligent modules. They us a 6 pin interface which has 3v3 beside the gnd (i.e. pin 0 on your circuit) so you have the following order..
    +3v3, gnd, then 4 i/os (which I am using the prop plug standard), so the propplug is the centre 4 pins of the 6 total.

    I am designing using this pinout. If you use it, make sure you get the correct orientation to the pcb edge. Avnet also have FPGA boards with this pinout.

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    · Home of the MultiBladeProps: TriBladeProp, SixBladeProp, website (Multiple propeller pcbs)
    · Single Board Computer:·3 Propeller ICs·and a·TriBladeProp board (ZiCog Z80 Emulator)
    · Prop Tools under Development or Completed (Index)
    · Emulators: Micros eg Altair, and Terminals eg VT100 (Index)
    · Search the Propeller forums (via Google)
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  • DavidMDavidM Posts: 630
    edited 2009-04-24 11:38
    HI Leon,

    i have room for the ferrite so I will update the board.

    Thanks

    Dave M
  • DavidMDavidM Posts: 630
    edited 2009-04-24 11:42
    HI Cluso99,

    I will have a look at the pin arrangement you suggested

    Thanks


    Dave M
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